Unlike the already-existing thumb detection, a touch may be labelled palm at
any time, not just during the initial touch down. This requires full
integration into the tap state machine to unwind properly. For most states, a
palm detection simply ignores the finger and reverts to the most recent state.
One exception is the case of two fingers down, one finger up followed by the
remaining finger detected as a palm finger. This triggers a single-finger tap
but with timestamps that may be from the wrong finger. Since we're within a
short tap timeout anyway this should not matter too much.
The special state PALM_UP is only handled in one condition (DEAD). Once a
touch is a palm we basically skip over it from then on. If we end up in the
DEAD state after a button press we still need to handle the palm up events
accordingly to be able to return to IDLE. That transition also requires us to
have an accurate count of the real fingers down (palms don't count) so we need
a separate nfingers_down counter for tapping.
https://bugs.freedesktop.org/show_bug.cgi?id=103210
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
The current debouncing code monitors events and switches on when events are
too close together. From then on, any event can be delayed.
Vicente Bergas provided an algorithm that avoids most of these delays:
on a button state change we now forward the change without delay but start a
timer. If the button changes state during that timer, the changes are
ignored. On timer expiry, events are sent to match the hardware state
with the client's view of the device. This is only done if needed.
Thus, a press-release sequence of: PRP sends a single press event, a sequence of
PRPR sends press and then the release at the end of the timeout. The timeout
is short enough that the delay should not be noticeable.
This new mode is called the 'bounce' mode. The old mode is now referred to as
'spurious' mode and only covers the case of a button held down that loses
contact. It works as before, monitoring a button for these spurious contact
losses and switching on. When on, button release events are delayed as before.
The whole button debouncing moves to a state machine which makes debugging a
lot easier. See the accompanying SVG for the diagram.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
The previous approach was to remember the last event and flush it at the right
time. The new approach is to update the device state during the frame and send
out the events at EV_SYN time.
This gives us two advantages: we are not dependent on the kernel order of how
events come in and we can process events depending on other events in the same
frame. This will come in handy later for button debouncing.
This is also the approach we have in the touchpad and tablet backends.
Two FIXMEs are left in place, the button debouncing code and the lid switch
code. Both need to be handled in future patches.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This has no real effect at the moment because the fallback interface doesn't
care much about SYN_REPORT, it processes events as they come in. But it's a
bug nonetheless, the process() callback expects correct event frames.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
We somewhat expect log message handlers to figure out how to prefix newlines
correctly anyway, but reducing the number of messages printed separately makes
the simple case better.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
There's no need for a custom error message everywhere, it's better to log the
current state and the event.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
needed for the razer blade keybard which provides multiple event nodes for
one physical device but it's hard/impossible to identify which one is the real
event node we care about.
https://bugs.freedesktop.org/show_bug.cgi?id=103156
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Touchpads that require the hysteresis do not have filtering in the firmware
and holding a finger still causes continuous cursor movements. This implies
that we get a continuous stream of events with motion data.
If the finger is on the touchpad but we don't see any motion, the finger is
stationary and the touchpad firmware does filtering. In that case, we don't
need to add a hysteresis on top.
https://bugs.freedesktop.org/show_bug.cgi?id=98839
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Once the lid is closed, the keyboard event listener is set up to open the lid
for us on keyboard events. With the right sequence, we can trigger the
listener to be added to the list multiple times, triggering an assert in the
list test code (or an infinite loop in the 1.8 branch).
Conditions:
* SW_LID value 1 - sets up the keyboard listener
* keyboard event - sets lid_is_closed to false
* SW_LID value 0 - is ignored because we're already open
* SW_LID value 1 - sets up the keyboard listener again
https://bugs.freedesktop.org/show_bug.cgi?id=103298
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
The main purpose of the edge zone is to detect palms in the area where we
cannot assume a full finger size and thus cannot use any other palm detection
mechanism. 8mm should be large enough that a finger should be detected based
on other properties (size, pressure, ...).
https://bugs.freedesktop.org/show_bug.cgi?id=103330
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
The main purpose of the edge zone is to detect palms in the area where we
cannot assume a full finger size and thus cannot use any other palm detection
mechanism. 8mm should be large enough that a finger should be detected based
on other properties (size, pressure, ...).
https://bugs.freedesktop.org/show_bug.cgi?id=103330
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Daniel Martin <consume.noise@gmail.com>
If we're adding an element that's not null or not a freshly initialized list,
chances are we haven't removed it from a previous list.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
Because on some devices the keyboard is where the fingers are holding the
device when in tablet mode.
https://bugs.freedesktop.org/show_bug.cgi?id=102729
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Split out the fallback-specific device handling from the more generic
evdev-specific handling (which is supposed to be available for all devices).
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Better for self-documentation than comments and makes it more obvious if we
initialize something wrongly.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Previously we only listened for events on the first one to come up, based on
the assumption that there can only be one internal keyboard. The Razer Blade
laptop keyboards come with with multiple event nodes, all looking like a
normal keyboard. The one that comes up first is one for special keys, so
typing on the internal keyboard after a lid switch does not toggle the write
state.
Fix this by allowing for up to 3 keyboard listeners for a lid switch.
https://bugs.freedesktop.org/show_bug.cgi?id=102039
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Avoid processing an event with a time later than the earliest timer expiry. If
libinput_dispatch() isn't called frequently enough, we may have e.g. a tap
timeout happening but read a subsequent input event first. In that case we can
erroneously trigger or miss out on taps, see wrong palm detection, etc.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
And instead disable it when we do get a proximity out.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Some devices like the UC Logic WP5540U has BTN_STYLUS but not BTN_TOOL_PEN.
While a kernel bug, let's just handle these correctly anyway.
https://bugs.freedesktop.org/show_bug.cgi?id=102570
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Yay-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Could be fixed in the kernel, but these tablets are effectively abandoned and
fixing them is a one-by-one issue. Let's put the infrastructure in place to
have this fixed once for this type of device and move on.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Yay-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
A touchpad that was disabled by toggling the sendevents option would come back
normally after a lid resume, despite still being nominally disabled.
https://bugzilla.redhat.com/show_bug.cgi?id=1448962
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
